In the production of a conventional precision casting mold, solutions such as aqueous silica sol or zirconia sol, ammonium zirconium carbonate, zirconium oxyacetate, and the like are used as binders. In recent years, precision casting of active metals represented by, for example, titanium alloys, has been realized, and various methods to attain this that use, for example, a zirconia sol, a basic inorganic salt, or ammonium zirconium carbonate, as binders for the production of precision casting molds have been proposed and will be described below.
A binder for precision casting that uses an aqueous zirconia sol having a secondary particle diameter of 2 to 30 nm and having a pH of 7 to 12, has been disclosed (Patent Document 1).
A binder for precision casting that uses a zirconia sol in which calcia, magnesia, or an oxide of a rare earth element is dissolved has been disclosed (Patent Document 2).
A stucco material for precision casting has been disclosed that includes 10 mm to 3 mm particles that are obtained by drying, crushing, and calcining a slurry having a total yttria and zirconia content that is from 30 to 95% by mass, a weight ratio of Y2O3/ZrO2 from 0.5 to 40, and a pH from 4 to 13 (Patent Document 3).
A manufacturing method for a mold in which a zirconia filler and zirconium oxyacetate serving as binders are used in a slurry for precision casting has been disclosed (Patent Document 4).
A manufacturing method for a mold in which a zirconia filler and ammonium zirconium carbonate serving as binders are used in a slurry for precision casting has been disclosed (Patent Document 5).
Patent Document 1: Japanese Patent No. 3123074; specification
Patent Document 2: JP-A 5-169185; specification
Patent Document 3: Japanese Patent No. 3138721; specification
Patent Document 4: JP-A 2000-126845; specification
Patent Document 5: JP-A 2001-18033; specification